YouTube has just as much of a monopoly in its category if not more than Facebook (with similar influence over society) yet we dont see the level of regular attacks (I'm not here to defend either, I'm a critic, but just pointing this out). Facebook total users: about 2.7 billion (with probably 80% dominance in its category). YouTube: about 2 billion but with a ~95% video stream dominance. The difference seems to be in the politics. I don't see the Atlantic or peers coming down on YouTubes dominance and influence.

Edit: As others have pointed out in here the difference might also be financial. Facebook publishes news articles and YouTube does not. A broken up Facebook offers a fractured publishing market and better pricing for news distribution.